One of the items of routine maintenance on a golf course is cutting the hole in the green. The placement is varied to alter the way the holes play, and to distribute wear evenly about the green surface.
The tool used to cut the holes in the green is called a cup cutter, or hole cutter. The cup cutter is a tool present at every golf course. The cup cutter is placed on the green at the position desired for the cup, and then is twisted into the ground. In this manner, a cylindrical element of earth is removed, and the cup is installed therein.
Clearly, the sharper the cutting edge of the cup cutter, the less work is required to place the cup. In that the cutter routinely slices through dirt, rocks, and roots, frequent sharpening is required to maintain a honed cutting edge.
Nowhere in the prior art does there exist a machine that effectively accomplishes this task. One disadvantage of the prior art devices is that they are designed to sharpen only one surface at a time. Because of the physical nature of the cup cutter, the cutting edge invariably has multiple surfaces.
Moreover, the cutting surfaces (termed "scallops") necessarily form a circle, and each individual scallop is itself arced. (See inset, FIG. 1.) Prior art sharpening devices are simply not equipped to handle the geometry of the cup cutter.